In an example of a semiconductor device, a semiconductor device including a plurality of memory cells arranged on a semiconductor substrate employs a memory cell formed with a MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) and a capacitor. Operations for writing, erasing and reading out information (electronic charges) on the capacitor are performed by driving the MOSFET. However, a reduction of the area of the capacitor along with miniaturization of the memory cell reduces the capacitance per memory cell. Further, this may cause errors in the operation for reading-out stored information or cause unintended erase operation to be performed on stored information due to irradiation of a-ray and the like.